[757labs] New Project Idea - Mini Wave Glider

Mon Oct 17 19:04:44 EDT 2011

According to the patent the front of the glider has a stiff front and back
section, with the center section relatively flexible. The fins are somewhat
flexible as well, but they're not attached to the main body of the glider.
When the wave rises under the platform it causes strain on the tether,
pulling water across the fins of the glider, and slightly deforming the body
of the glider. At the rise of the wave the strain on the tether is lessened,
the glider sinks, the fins rotate the other direction and begin to pull
against the platform.

In other words the flipping of the vanes is not motorized, its kind of a
side effect. And its really brilliant.

Something like a fiberglass/carbon fiber would be good for the center
section. Strong and flexible. Figuring out the balance of the displacement
of the glider and the buoyancy of the platform can be done with some trial
and error. I think the hardest part would be the design of the fins/vanes.
That's some deep fluid dynamics territory there. (Or it could be really
simple... heh)

On Mon, Oct 17, 2011 at 3:57 PM, Michael Ross <757labs at oneross.com> wrote:

> Steve: Sorry, didn't really know what phrase to use, I was trying to say
> "hunk of metal moving back and forth between coils to generate electricity".
>  The weighted fin idea is what I was heading towards with the 'Salter's
> Duck" thing (Salter was a guy who wanted to use big honking weighted fins to
> do what you described to described during the oil crisis in the '70s).
>
> Trevor: I'm not too sure on the physics, but I think the forward motion
> relies on the rising float pulling up on the submerged platform, forcing
> water down across the vanes and towards the back...  If you have too much
> play with a flywheel you'll loose most of your ability to move forward.
>  Same basic concept as the linear generator (up/down motion of tether =>
> voltage/current) but better communicated and probably more efficient.  I
> think that'd just leave either finding the right amount of tether movement
> to still generate forward motion while creating useful amount of electrical
> power, or some way of switching between a fixed tether for moving and a
> moving tether for power generation.
>
> http://www.icrepq.com/icrepq-08/380-leao.pdf has a bunch of different
> wave-power conversion technologies that might inspire something useful (but
> if we trailed pelamis tentacles it might look like a sea creature and get
> eaten).
>
> Also, I just took a second look at the WaveGlider pdf and noticed the vanes
> switch position on the upward and downward motion, which I'd missed before.
>  Does anyone know if they just do that naturally because of their shape or
> if they're actuated somehow?
>
>
> On Mon, Oct 17, 2011 at 2:25 PM, Trevor Lewis <trevorl.salad at gmail.com>wrote:
>
>>
>> I'm not familiar with Salter's ducks, but according to good 'ol wikipedia
>> (and correct me if I'm wrong, I just did a quick skim) it generates power
>> based on the impact of a wave. It looks like the glider uses the rise and
>> fall of the wave to pull the float forward. Wouldn't a simple
>> dynamo/flywheel combination be an easier way to generate power? The
>> upward rise of the wave extends the tether, causing the flywheel to spin,
>> and generating current. The downard fall of the wave retracts the tether,
>> resetting the system. I think we would end up generating more power than we
>> could reasonably use, even in relatively calm seas.
>>
>> On Mon, Oct 17, 2011 at 1:17 PM, Michael Ross <757labs at oneross.com>wrote:
>>
>>> It might be possible to generate electrical power from wave motion when
>>> reserves get low (maybe dual-purpose the blades on the underwater platform
>>> to act as Salter's Ducks for a few hours on cloudy days with high seas, or
>>> maybe just a simple plunger core linear generator).  It would increase
>>> complexity (and probably be some pretty tough engineering to have veins that
>>> would operate efficiently in both mechanical-locomotion/steerage mode and
>>> Salter-Duck mode) but provide a second source of electrical power.
>>>
>>>
>>>  On Mon, Oct 17, 2011 at 12:42 PM, Trevor Lewis <trevorl.salad at gmail.com
>>> > wrote:
>>>
>>>>
>>>> That is a damn cool project. Really graceful design. I wonder if it
>>>> would be possible to print all the components for a 1/4 scale version of the
>>>> glider, that would certainly make it affordable. At smaller scales the
>>>> design might have to be tweaked to increase its odds of survival in heavy
>>>> seas.
>>>>
>>>> At 1/4 scale the float is 52x15cm, the glider is 10x47.75cm and the
>>>> wings are 26.75cm. Still actually a pretty respectable size.
>>>>
>>>> Of course a scale version will also reduce the surface area for the
>>>> solar panels. Think there would be enough juice to power an APRS system,
>>>> GPS, and brain? I would love to be able to fit an acoustic recorder in the
>>>> system, bet we could get some interesting stuff.
>>>>
>>>>
>>>>
>>>> On Sat, Oct 15, 2011 at 7:52 PM, Almost_There at COX.Net <
>>>> Almost_There at cox.net> wrote:
>>>>
>>>>>
>>>>> 757 Labs - Mini Wave Glider;
>>>>>
>>>>> http://757Labs.Org/wiki/Mini_**Wave_Glider<http://757labs.org/wiki/Mini_Wave_Glider>
>>>>>
>>>>> We should make a Mini Wave Glider; a scaled down version of Liquid
>>>>> Robotics Autonomous Wave Glider (there's is roughly surfboard size, we
>>>>> should make one 1/4 to 1/2 that size.)  Simply put, it converts the up/down
>>>>> motion of waves to forward thrust (free locomotion.)  Liquid Robotics has
>>>>> demonstrated long duration missions of over 2500 miles and over 400 days
>>>>> without any intervention.  We could start small and work our way up, but
>>>>> ultimately have it autonomously cruse up & down the east coast (or if we're
>>>>> really brave, cross the Atlantic.)
>>>>>
>>>>> * Solar power recharges batteries
>>>>> * Guided by GPS
>>>>> * Reports location and sensor data by APRS
>>>>>
>>>>> See...
>>>>> http://LiquidR.com/ <http://liquidr.com/>
>>>>>
>>>>> http://LiquidR.com/files/2011/**05/WaveGlider_Web.pdf<http://liquidr.com/files/2011/05/WaveGlider_Web.pdf>
>>>>>
>>>>> http://www.YouTube.com/watch?**v=eATawqVOXWI<http://www.youtube.com/watch?v=eATawqVOXWI>
>>>>>
>>>>> http://patft.uspto.gov/**netacgi/nph-Parser?Sect1=PTO1&**
>>>>> Sect2=HITOFF&d=PALL&p=1&u=%**2Fnetahtml%2FPTO%2Fsrchnum.**
>>>>> htm&r=1&f=G&l=50&s1=7,371,136.**PN.&OS=PN/7,371,136&RS=PN/7,**371,136<http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=7,371,136.PN.&OS=PN/7,371,136&RS=PN/7,371,136>
>>>>> (You can copy patents, as long as you don't profit from it i.e. free
>>>>> for personal use.)
>>>>>
>>>>> ______________________________**_________________
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>>>>> If we knew what we were doing it wouldn't be research.
>>>>>
>>>>
>>>>
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